Mother Nature is cranking up the summertime heat in Austin and Houston. New data from Climate Central shows the Capital City and Bayou City are among nine major U.S. cities that now experience at least 50 more days per year with above-normal summer temperatures than they did in 1970.

Other Texas cities that made the list were El Paso, McAllen, and Tyler. Climate Central is a nonprofit organization that provides climate science research and analysis.

“Climate change is driving increasing temperatures across Texas and causing hotter summers. Austin and Houston now experience at least 50 more days above normal than they did in 1970,” said Kristina Dahl, vice president of science at Climate Central. “This isn’t just about discomfort; it’s about the growing risks to public health and infrastructure. We must prioritize climate resilience and stop burning fossil fuels to address these escalating challenges.”

Outside Texas, cities on the list were Reno, Nevada; Albany, Georgia; Las Cruces, New Mexico; and New Orleans.

For Austin, the number of above-normal-temperature summer days climbed by 50 from 1970 to 2024, according to Climate Central. During that period, the average summer temperature in Austin increased by 4.7 degrees.

In Houston, the quarter-century increase in the number of above-normal-temperature summer days was even higher — 56. The average summer temperature there rose by 4.6 degrees from 1970 to 2024, according to Climate Central.

Climate Central says that of the 242 cities it analyzed, 97 percent had seen a rise in the number of hotter-than-normal summer days (June, July, and August) between 1970 and 2024. The study found the average jump in summer temperatures since 1970 was 2.6 degrees.

The cities that warmed up the most from 1970 to 2024 were:

• Reno, up 11.3 degrees.
• Boise, Idaho, up 6.3 degrees.
• El Paso, up 6.2 degrees.
• Las Vegas, up 6.1 degrees.
• Salt Lake City, up 5.9 degrees.

“As heat-trapping pollution continues to warm the planet,” Climate Central explains, “summer temperatures are arriving earlier and getting hotter — and dangerous heat extremes are becoming more frequent and intense.”

Although the study does not attribute specific causes to each city's warming, it does link a related study about urban heat islands, city centers that are hotter than their surroundings due to how infrastructure is built. On a map of hotspots, all major Texas metros stood out.

Climate Central’s study was based on weather data from the National Oceanic and Atmospheric Administration (NOAA).